Help plz
1. If the pH of a solution is 6.23 then what is the [H+]
a.1698243
b.5.888 x 10-7
c.0.7944
d.1 x 10-6.23

2.Consider the mystery acid X2Y . If this acid is known to contain only two different elements, which of the following below could be the identity of the mystery acid
a. H2N
b. H2Br
c. O2Cl
d. H2S

3.Consider the mystery base with the generic formula XY3 . Remembering that this is a base and not an acid, which of the following below could be the formula of the mystery base
a. HClO3
b. AlF3
c. Al(OH)3
d. FeOH

4.Calculate the pH of a solution that has a hydronium ion concentration of 4.67 x 10-12.
a.1
b.-11.33
c.12
d.11.33

5.Is the solution above in question #4 an acid or a base?
a. acid
b. neither , it is neutral
c. base
d. cannot be determined